when doing something surprising, say so

[Ben Finney]

Martin Pool <mbp at canonical.com> writes:

> I think we should add this to our general ui principles, or perhaps
> just pay more attention to it:
> 
> When we're doing something that would have surprising impacts on the
> user, we should tell them we're doing it.

I think this is good, and it is a subset of a greater UI principle:

    The Principle of Least Astonishment states that the result of
    performing some operation should be obvious, consistent, and
    predictable, based upon the name of the operation and other clues.

    <URL:http://c2.com/cgi/wiki?PrincipleOfLeastAstonishment>

So, it's good to warn when the program will do something astonishing,
but even better is to hew to behaviour that *isn't* astonishing (by the
above definition).

-- 
 \     “I went to the cinema, it said ‘Adults: $5.00, Children $2.50’. |
  `\          So I said ‘Give me two boys and a girl.’” —Steven Wright |
_o__)                                                                  |
Ben Finney